2002 F-350 4x4 repair question

[Happy Gilmore]

My 4x4 quit working. No light on the dash turns on and doesn't engage. I have Warn Manual hubs. Yesterday I replaced the switch on the dash(the light was burnt out previous to it stopping working) and the t-case actuator motor. I bought a new relay at the suggestion of a friend but, I have no idea where it goes? Anyone have any other suggestions? I think my actuator motor may have been fine because, I still have no 4x4. Total parts were only $200 so far so, at 200K miles I don't mind replacing everything as preventative maintenance but, it still isn't working?

I'm now crossing the fingers that it is just a $12 relay that went bad and I don't know where to plug in the little black box.

[Caseyd]

I'm now crossing the fingers that it is just a $12 relay that went bad and I don't know where to plug in the little black box.

Fuse/Relay panel under the hood (same place as wiper relay)

By the way that is just a guess since I dont own a ford, nor am i a mechanic 

[6x6in6]

Can you hear if it is trying to engage?
If yes, have you thoroughly checked the vacuum lines at the actuator pump and chased the lines for connections/damage?
A slim chance, but it happens.  The o-ring seals on the back side of the hubs go bad.  This will case loss of vacuum and not allow to engage.
More often than not it's vacuum issue.

[jackelope]

I'm now crossing the fingers that it is just a $12 relay that went bad and I don't know where to plug in the little black box.

Fuse/Relay panel under the hood (same place as wiper relay)

By the way that is just a guess since I dont own a ford, nor am i a mechanic 

What Casey is really saying is that it could be that or it could also be your hubcap fluid.

[Happy Gilmore]

I'm now crossing the fingers that it is just a $12 relay that went bad and I don't know where to plug in the little black box.

Fuse/Relay panel under the hood (same place as wiper relay)

By the way that is just a guess since I dont own a ford, nor am i a mechanic 

On the drivers side there are three un-labeled boxes with 6 relays which are all the same. I guess which one specifically? Without a voltage tester, is there a way to tell if they are bad? I'd replace them all but, at $13 each- starts gettign a little spendy..

[Happy Gilmore]

I switched to Warn Manual hubs. My vacuum lines are plugged but, it doesn't even try to engage. No light comes on. No noise, no clicking, nothing.

[Happy Gilmore]

found a wiring diagram. Pulled the harnesses back a little and cleaned wires with a Q-tip to find the color combination. For you PS guys, the 4x4 relay switch is inside the black box on the drivers side, closest to the fender. There are two relay plugs. One closest to the fender is the 4x4 motor relay switch. Everything is working again. I'm guessing this probably could have been a $12 fix because i put the new actuator motor in and it still didn't work. At this point, with 200K on the truck, I'll leave it in rather than putting the old one back in and taking the new one back.

Anyone's 4x4 not working and need a actuator motor? I'll give it to you for free.

[Caseyd]

I'm now crossing the fingers that it is just a $12 relay that went bad and I don't know where to plug in the little black box.

Fuse/Relay panel under the hood (same place as wiper relay)

By the way that is just a guess since I dont own a ford, nor am i a mechanic 

What Casey is really saying is that it could be that or it could also be your hubcap fluid.

HA I was right..........dont forget to check that hubcap fluid though while your at it 


Glad you got it working Happy

[Happy Gilmore]

hub cap oil...I checked it, filled it up and they work fine!!

Actually- I take back the thing being "free"....I'd only like my core charge back which was $26 dollars if it works to fix your truck if you need one! LOL- Thanks for the help!

It was actually the easiest repair I've ever made. Dropped the skid plate with four bolts. The actuator motor came out very easily with three bolts. The only issue I had was when I was backing out the middle bolt, I wasn't looking at it because of dirt falling in my face. I backed it out all the way into the front U-joint on the drive shaft. I had to fight with it a while to get my socket wrench switched back to tighten instead of loosen. I backed it off right into the u-joint and couldn't move it......a few selected cuss words later and a pocket knife blade, short socket instead of deep socket and it was off.....for a few moments I though I would be cutting it off! haha...whoops....need some clear safety glasses....truck dirt/grease in your eyes and contact lenses don't get along real well....

[jeepasaurusrex]

Do you have the transmission in neutral and your foot on the brake when trying to engage 4x4? That is what is required for mine to work.

[Happy Gilmore]

Do you have the transmission in neutral and your foot on the brake when trying to engage 4x4? That is what is required for mine to work.

No- it's always been shift on the fly. Book says under 50mph. I've always had the general rule of not engaging it when under any power or stopped. Since ditching the auto hubs last year, I have to stop to turn them anyways so, no...

I did try putting it in nuetral to put in 4x4. Confident it was just the relay which was bad now. That's ok. From the forums I've read they usually go out at bad times so, I feel better having a new one on. I use the 4x4 about 3 times a week at minimum when out in the fields dog training during the wet seasons so....like I said, with 200K on my truck, I don't mind having a little better piece of mind parts are all new from the relay to the switch to the motor. Not to mention I'm leaving for South Dakota next week for two weeks and I hear the weather can be bad out there and the mud is slopy.

I did finally decide on tires too- The least expensive I could find was BFG Mud Terrains. $211 each at Discount. 255-75-16" PG

[Happy Gilmore]

Do you have the transmission in neutral and your foot on the brake when trying to engage 4x4? That is what is required for mine to work.

That reminds me of something- about 5 years ago mine got really finicky about what position the shift lever was in to engage. At that time, (Les Schwab guys showed me this) it was a crappy little plastic collar that fits around your shift level shaft. There is a little brace that keeps your shift level in alignment on top of your steering column.

The plastic ring slides out from the brace and there is a sensor which starts to malfunction due to the level being sloppy and moving around.

Take the ignition switch plastic off, (right where your key inserts) it prys off with a screwdriver, remove the column covers. Its a couple philips heads. follow the shifter linkage back and there is a plastic ring that keeps the "play" out of the shift level. If your lever can move around, the sensor might not be picking up that your truck gear is in a position allowing it to engage. I also left the wire on it unplugged so, I can have my keys in the ingnition without the stupid bell ringing constantly.

I found mine was installed backwards allowing it to slide out of the little "U-bolt" that keeps it tight. The plastic is slit so it can pop on and off. I put some gorilla glue on it, put the u-bolt type brace back on and didn't have a problem again.

[Happy Gilmore]

so, maybe not so easy after all. After putting a new relay in it worked fine right after I posted. Now it won't engage again? Wonder if something is shorting out the relay or, maybe I got a bad motor or relay? Not sure how/where to trouble shoot from here. Making a trip out to Monroe. Will stop by a friends' shop and see what they have to say? Maybe ask Schwab how they plugged the vacuum lines? damnit! thought i had this one solved!!! 

[jeepasaurusrex]

Gas or diesel? Mine is a diesel and when I put the Warn hubs on, I disconnected the vacuum line at the distribution block and put a vacuum cap on it. That way there is no lines to leak.

[jackelope]

Happy-
PM sent.